1. Technical Field
The present invention relates to a substrate panel having substrate units coupled thereon.
2. Description of the Related Art
In the manufacturing process for a printed circuit board, plating processes are of utmost importance. In proceeding with such plating processes, clamp contacts 111, 112 may be located at the edges of a substrate panel 10, as illustrated in FIG. 1, by which to supply an electric current to the substrate units 121. The clamp contacts 111, 112 are the points to which a clamp is coupled, and thus may be changed in accordance to the position where the clamp is coupled. The clamp contacts 111, 112 may not necessarily be externally marked. There may be multiple substrate units 121, and there may be smaller unit substrates coupled inside each substrate unit 121.
The amount of current supplied to each substrate unit 121 may vary according to its position, so that deviations occur in the degree of plating. This can be caused by a greater amount of electric current flowing through those bus lines that are closer to the clamp contacts.
FIG. 2 is a diagram representing the density of electric current after plating a conventional substrate panel 10 in a plating bath. The more closely spaced lines denote areas of higher current densities, and it can be seen that a greater amount of electric current is distributed to substrate units closer to the clamp contacts. As a result, the electric current can be distributed unevenly over the substrates, as in the diagram shown in FIG. 2. This may occur because bus lines 122 located in positions far from the clamp contacts 111, 112 may provide a relatively lower supply of electric current.